Ignition timing control system for internal combustion engine

Abstract

An ignition timing control system for an internal combustion engine is provided to ensure stable combustion without causing misfire or knocking, by properly setting ignition timing in the compression stroke injection mode, thereby improving drivability. The ignition timing control system for the engine, that directly injects fuel into the cylinders and that is operated by switching the fuel injection mode between an intake stroke injection mode and a compression stroke injection mode, includes a fuel injection timing-setting device for setting a fuel injection timing according to an engine speed of the engine and a fuel injection amount, a basic value-setting device for setting a basic value of ignition timing according to the engine speed of the engine and the fuel injection timing, and an ignition timing-setting device for setting ignition timing in the compression stroke injection mode by correcting the basic value according to a detected air-fuel ratio.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an ignition timing control system for an internal combustion engine which directly injects fuel into cylinders and is operated by switching the fuel injection mode between a suction stroke injection mode in which fuel is injected during the suction stroke and a compression stroke injection mode in which fuel is injected during the compression stroke, the ignition timing control system controlling ignition timing in the compression stroke injection mode.BACKGROUND ART[0002]Conventionally, as an ignition timing control system for an engine, one disclosed in Patent Literature 1 is known. This engine is of a direct fuel-injection type which is configured to directly inject fuel into cylinders, and in the engine, homogeneous combustion in which fuel is injected during the suction stroke and a homogeneous air-fuel mixture generated in a combustion chamber is burned and stratified combustion in which fuel is injected during the c...

AI Technical Summary

Benefits of technology

The patent describes a method of optimizing ignition timing in an engine to improve combustion and driving performance. The method takes into account the air-fuel ratio and the amount of internal EGR (exhaust gas recirculation) in the engine. By adjusting the ignition timing accordingly, the method ensures stable combustion and reduces the likelihood of misfires or knocking. Overall, the method improves the engine's efficiency and performance.

Problems solved by technology

However, in the conventional ignition timing control system, ignition timing for the stratified combustion is set according to only the engine speed and the basic fuel injection amount or the target engine torque, and hence it is not necessarily possible to properly set the ignition timing, depending on the operating conditions of the engine.

As a result, a misfire or knocking is caused, making it possible to obtain stable combustion, and hence there is a fear that drivability is lowered.

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